Bacterial communities of the oysters crassostrea corteziensis and c. Sikamea of cospita bay, Sinaloa, Mexico

Abstract

This work aimed to quantify the bacterial loads and determine the taxonomic composition of the microbial communities of oysters Crassostrea corteziensis and C. sikamea, as well as the surrounding waters of Cospita Bay, using two sets of samples (M1 and M4) obtained in the dry season and two (M2 and M3) in the rainy season. Bacterial loads were quantified with the viable count technique and out of the 320 strains isolated for their different morphologies, 84 were identified with molecular techniques to the species level. These species pertained to the families Vibrionaceae, Bacillaceae, Brucellaceae, Micrococcaceae, Pseudoalteromonaceae, Rhodobactereceae, Shewanellaceae and Staphylococcaceae. The higher concentrations of total bacteria were in the rainy season (samples M2 and M3), when families Vibrionaceae and Brucellaceae dominated. The highest Vibrio spp. and Pseudomonas spp. concentrations were in winter (samples M4). Probably because of its poor health conditions, the Kumamoto oyster C. sikamea had the highest diversity of bacterial species and the highest number of known pathogens for aquatic organisms.